Engine starter



Sept. 8 1931. w. 1.. mammal 1,822,163

mammal-AMER Original Filed Dec. 24, 9 znsheevtskshen l Sept. 8, 1931. w. L. M GRATH ENGINE STARTER Original Filed Dec. 24, 1921 2 Sheets-Sheet 2 reamed Sept. 8, 1931 UNITED STATES PATENT OFFICE WILLIAM L. MGGRATH, O]? ELMIRA, NEW YORK, ASSIGNOR TO ECLISE MACHINE COMPANY, OF ELMIBA, NEW YORK, A OORPOBA'IION OF NEW YORK ENGINE STARTER Application filed December 24, 1921, Serial No. 524,758. Renewed August 3, 1927.

My invention relates to engine starters, particularly to the drive or transmission portion thereof between the prime mover, such as an electric motor and a member of the en- 7 gine to be started, such as the flywheel. The

ment or meshing between the driving member of the drive such as a pinion and the driven member or flywheel gear. Speaking more in detail, provision is made in a drive embodying myinvention for positive and direct action upon the driving member or pinion to cause a slight rotation thereof whenever such pinion is stopped in its longitudinal movement as when abutting occurs between the pinion teeth and the flywheel teeth. The various features of advantage and utility inthe construction and mode of operation of my new form of drive will be apparent from the description hereinafter given.

Tn the drawings Fig. 1 is an elevation of a starter system with a drive embodying my invention, having a portion thereof broken away; Fig. 2 a view similar to Fig. 1 but showing the relative position of the parts in case of abutting of the pinion teeth and flywheel teeth; Fig. 3 an elevation showing t e relative position of the parts when the pinion is in full meshwith the flywheel, that is, in driving position; Fig. 4 a central sectional elevation of the drive; Figs. 5 and 6 sections on the corresponding section lines of Fig. 4;

Fig. 7 a pers ective of the pinion and its cam member; ig. 8 a'perspective of the nut and its cam member "and Fig. 9 an elevation of the torsion spring associated with the cam members.

In the drawings I have shown one embodiment of my invention without intention of restricting myself thereto, it being understood that my invention is equally applicable to the inboard type of drive whereas the outboard type is herein shown and also to the indirect geared type whereas the direc geared type is here shown. I

drive with which my present drive has certain features in common as to construction and operation. As shown, a driving head 3 is operatively connected with the driving or armature shaft 2 in suitable manner as by means of the stud 4 which also serves to anchor to such head the drive spring 5 whose other end is connected by means of the stud 6 to the head 7 of a sleeve. This sleeve surrounds and is mounted upon the driving shaft 2 and is provided with a screw threaded portion 8 and a plain portion 9 and carries at its outer end an abutment in the form of a stop nut 10.

The driving member which is here in the form of a pinion 11 has a smooth bore and is loosely mounted on the sleeve as respect both the screw threaded portion and the smooth portion. The outer end of the pinion cooperates with a collar 12 which fits and slides upon the smooth portion 9 of-the sleeve and between which and the stop is interposed a light coil spring 13. In the present application I make no claim for this particular con-- struction inasmuch as it forms the subject matter of an application previously filed by me in the United States Patent Oflice.

The driving'member or pinion is provided, either as an integral or a separate structure, with a cam member which is clearly shown in Fig. 7. This cam member comprises, in the resent instance a disk or ring l l which as s own and by preference is a separate structure secured in any suitable manner to the pinion at the inner or non-engaging end thereof. This ring is provided with projecting similar cam members 15 arranged on diametrically o posite sides of the ring and having cam aces 16 which are inclined to the axis of rotation of the shaft and pinion as illustrated in Figs. 1, 2 and 3. i

A pinion 11 is the driving member proper but in reality the driving member comprises two physically separate but cooperating parts, one being the pinion and the other a nut 17 which is screw threaded upon the threaded portion 8 of the sleeve. This nut is likewise provided with a cam device which may be either integral or separate but here shown as integral, the same comprising the flange or disk portion 18 and two projecting similar cam members 19. These cam members are complementary to the cam members 15 of the pinion and are likewise provided with similar inclined cam faces 20 which cooperate directly with the faces 16 of the other cam device.

A suitable cup or shell 21 encloses these cam devices and is secured to one of them being in the present instance secured to the cam ring 14 by the screws 22, Fig. 5. This cup is provided at its inner end with an inturned marginal flange 23 which cooperates with the outer face of the disk and thereby limits the longitudinal displacement of the cam devices and also the nut and pinion.

Between the cam devices a suitable spring is interposed for the purpose of holding the cam faces of such devices-in contact. This spring 24 surrounds the screw sleeve and its bent ends 25 are anchored in the cam rings or disks respectively. In order that different degrees of tension may be provided, the disk 18 has a series of anchoring holes 26, as shown in Figs. 6 and 8.

Describing a cycle of operation and starting with the parts in the normal position shown in Fig. 1, when the electric motor is operated and the driving shaft 2 and screw sleeve are rotated, the driving member structure including the nut and pinion together with their ass ciated parts are carried longitudinally of the screw sleeve or shaft, toward the left, Fig. 1. In the event that in this longitudinal movement of the pinion, register is not obtained between the pinion teeth and the flywheel teeth and such teeth therefore abut as shown in Fig. 2, the longitudinal movement of such pinion will consequently be stopped but the nut will continue to ad- Vance longitudinally due to the screw action between it and the screw shaft, with the result that the cam faces 16 and 20 which are always in contact, will cooperate and will slide upon each other as shown in Fig. 2 when compared with Fig. 1. In this sliding movement the inion is given a slight rotary movement in the direction indicated by the arrow in Fig. 2 and thereby displaces the 55 pinion from its abutting position and brings the pinion teeth in proper register with the flywheel teeth. The longitudinal movement o the. driving member assembly will thereupon continue until the pinion is brought to 60 rest against the collar 12 which is itself stopped in its longitudinal movement by the stop nut 10. Thereupon the continued and final longitudinal movement of the nut will cause a closing up of the cam members and i M result in a substantially solid rotary driving connection between them as shown in Fig. 3. When the engine starts on its own power, the pinion is automatically demeshed in the manner usual in the screw shaft type of drive and the parts are restored to the normal position shown in Fig. 1. y

In order to cause the pinion and its associated parts to stop dead on its return movement after being demeshed from the flywheel and to prevent any possibility of the bouncing of such parts back towards the flywheel, suitable means may be provided, such as means for stopping the pinion itself instead of the nut. For instance and as shown here in, the cup 21 is provided with a projection or tooth 27 adapted to engage a positive stop on the screw shaft such as the square shoulder 28 in the head 7 of such shaft. As a result it is the pinion which is directly stopped.

The drive above described and illustrated in Figs. 1 to 4 is provided with the type of spring usually employed in the Bendix drive, that is a spring with its coils, when idle, slightly separated so as to permit of yielding longitudinal movement of the screw shaft in case of abutting of the pinion teeth and flywheel teeth, as set forth in BendiX'Patent No. 1,125,935 issued Jan. 26, 1915. However, with the incorporation and use of my invention, it is unnecessary to have a spring with its coils thus spaced apart inasmuch as such longitudinal movement of the screw shaft is unnecessary and does not occur because proper slight rotary movement of the pinion is enforced and proper register of the teeth thereby effected. Moreover, with the use of my invention, it is possible to have these coils in contact when idle, that is to eliminate the spaces between the coils, with the result that the drive attains a new function. This function consists in the frictional resistance possessed by the coils, when the spring is wound up and about to deliver its stored up energy during the deceleration action of the spring. It is desirablev that this actlon be not substantially instantaneous or extremely rapid as in the case of the usual type ofspring, but shall be somewhat delayed. To this end, these coils are in contact when idle, as shown in the spring 29, illustrated in Fig. 10, so that frictional resistance to unwinding of such spring is provided.

In so far as the feature of enforced meshing in its broader aspect is concerned, the particular construction and type of drive is immaterial and likewise the use or absence of the drive spring and the use of any particular form of spring are immaterial.

I claim 1. An engine starter drive including a rotatable member, a two part driving member mounted thereon, whose parts have a limited rotary movement one with respect to the other, the first of said parts being operatively connected with the rotatable member mounted thereon, whose movement one with respect to the,

for longitudinal movement thereof and rotary movement therewith, and the second part being movable longitudinally by the first part to engage a member of the engine to be started, and meanscooperating with said two parts for causing a slight rotation of said second part with respect to the first part whenever said second part is arrested in its longitudinal movement,

. 2. An engine starter drive including a rotatable member, a two part driving member mounted thereon, whose parts have a limited rotary movement one with respect to the other, the first of said parts being operatively connected with the rotatable member for longitudinal movement thereof and rotary movement therewith, and the second part be ing movably longitudinally by the first part to engage a member of the engine to be started, and means dependent for operation upon the continued longitudinal movement of said first part and the arrest of said second part for causing a slight rotation of such latter part with respect to the first part.

3. An engine starter drive including a rotatable member, a two part driving member parts have a limited rotary other, the first of said parts being operatively connected with the rotatable member for longitudinal movement thereof and rotary movement therewith, and the second part being movable longitudinally by the first part to engage a member of the engine to be started, and members carried by said two parts respectively and directly coacting to move the second part longitudinally into engagement with the engine member and to slightly rotate it with respect to the first part in case of its arrest in such movement.

4. An engine starter drive including a rotatable member, a two part driving member mounted thereon, whose parts have a limited rotary movement one with respect to the other, the first of said parts being operatively 1 connected with the rotatable member for longitudinal movement thereof and rotary movement therewith, and the second part being movable longitudinally by the first part to engage a member of'the engine to be started, and complementary cam members on said two parts respectively.

5. An engine starter drive including a rotatable member, a driving member mounted thereon for longitudinal movement thereof and rotary movement therewith and having a'receptive end surface, and longitudinally movable cooperative means having provision to act against such surface of said driving member to slightly rotate the latter whenever longitudinal movement of said cooperative means is continued after the longitudinal movement of said driving member has been arrested.

6. An engine starter drive including a ro- 'ber mounted thereon tatable member, a driving member mounted thereon for longitudinal movement thereof and rotary movement therewith, and means acting upon one end of such driving member to slightly rotate it whenever it stops in its longitudinal movement, said means comprising two complementary cams, one connected with said end of the driving member and .the other operatively connected with the rotatable member for longitudinal movement thereof and rotary movement therewith.

7. An engine starter drive including a rotatable member,va two part driving member mounted thereon for longitudinal movement thereof and rotary movement therewith and -means located between and operatively connecting said two parts and permitting limited longitudinal and rotary movements one with respect to the other, said two parts being arranged in axial alinement, said means comprising cam members carried by said two parts respectively. Y,

8. An engine starter drive including a rotatable member, a two part driving member mounted thereon for thereof and rotary movement therewith and means located between and operatively connecting said two parts and permitting limited longitudinal and rotary movements one with respect to the other, said two parts being arranged in axial alinement, said means comprising cam members carried by said two parts respectively and held together yieldingly in a normal position rotarily.

'9. An engine starter drive including a rotatable member, mounted thereon for longitudinal movement thereof and rotary movement therewith and means located necting said two parts and permitting limited longitudinal and rotary movements one with respect to the other, said two parts being arranged in axial alinement, said means comprising cam members carried by said two parts respectively and a torsion spring connected at its ends to said two cam members for yieldingly holding them together in amormal positionrotarilyQ 10. An engine starter rotatable member, a two'part driving memfor longitudinal movement thereof and rotary movement therewith, said parts being arranged in axial alinement and one of them being loosely mounted on the rotatable member and the other operatively connected therewith, the adjacent ends of said two parts carrying cam members provided with complementary surfaces which are at an angle rotation of the two pa'rts.

11. An engine starter drive including a rotatable member, a two part driving member mounted thereon for longitudinal movement thereof and rotary movement therewith, said parts being arranged in axial longitudinal movement a two part driving memberdrive including a to the axis of alinement and one of them being loosely mounted on the rotatable member and the other operatively connected therewith, the adjacent ends of said two parts carrying cam members provided with complementary surfaces which are at anangle to the axis of rotation of the two parts, and means for holding said two parts yieldingly in a normal position rotarily.

12. An en 'ne starter drive including a rotatable mem r, a two part driving member mounted thereon for longitudinal movement thereof and rotary movement therewith, said parts being arranged in axial alinement and one of them being loosely mounted on the rotatable member and the other operatively connected therewith, the adjacent ends of said two parts carrying cam members provided with complementary surfaces which are at an angle to the axis of rotation of the two parts, and a torsion spring connecting the two cam members for holding them in a normal position rotarily.

13. An engine starter drive including a rotatable member, a two part driving member mounted thereon for longitudinal movement thereof and rotary movement there- 7 with, said parts being arranged in axial alinement and one of them being loosely mounted on the rotatable member and the other operatively connected therewith, the adjacent ends of said two parts carrying cam members provided with complementary surfaces which are at an angle to the axis of rotation of the two parts, and a cup secured to one of the cam members and adapted to loosely engage the other one and thereby limit the disengagement longitudinally of the two parts of the driving member.

14. An engine starter drive comprising a rotatable screw shaft, and a driving member formed in two parts, one part being a pinion loosely mounted on the shaft and the other part being a nut threaded on the shaft, said pinion and nut being disposed in axial alinement and carrying between them cam members acting as the driving medium between the nut and pinion and permitting a slight rotary move ent of the pinion relative to the nut.

15. An engine starter drive comprising a rotatable screw shaft, and a drivingmember formed in two parts, one part being a pinion loosely mounted on the shaft and the other part being a nut threaded on the shaft, said pinion and nut being disposed in axial alinement and carrying between them cam members acting as the driving medium between the nut and'pinion, said members having complementary cam surfaces which are inclined to the axis of rotation of the pinion and nut and which permit of a slight rotary movement of the pinion with respect to the nut and also a relative longitudinal movement one with respect to the other.

16. An engine starter drive comprising a formed in two parts, one part being a pinion loosely mounted on the shaft and the other part being a nut threaded on the shaft, said pinion and nut being disposed in axial alinement' and carrying between them cam members acting as the driving medium between the nut and pinion and permitting a slight rotary movement of the pinion relative to the nut, and a torsion spring encircling the shaft and connected at its ends respectively to the two cam members.

17. An engine starter drive including a driving member adapted to move longitudinally to engage a member of the engine to be started, and means mounted for longitudinal movement and, in its longitudinal movement continued after an improper arresting of the longitudinal movement of the driving member, cooperating with such driving member to enforce proper engagement thereof with the engine member, said driving member and sai means being in tandem arrangement and rotatable together.

18. An engine starter drive including a driving member adapted to move longitudinally to engage a member of the engine to be started, and means mounted for longitudinal movement and, in its longitudinal movement continued after any improper arresting of the longitudinal movement of the driving member, cooperating with such driving member to partially rotate it as an incident of such continued longitudinal movement of said means, thereby enforcingproper engagement with the engine member, said driving member and said means being in tandem arrangement and rotatable together.

19. An engine starter drive including a driving member adapted to move longitudinally to engage a member of the engine to be started, and means mounted for longitudinal movement and, in its longitudinal movement continued after any improper arresting of the longitudinal movement of the driving member, cooperating with such driving member to partially rotate it as an incident of such continued longitudinal movement of said means, thereby enforcing proper engagement with the engine member, such means comprising a device operated to enforce partial rotation of the driving member when thus arrested and normally rotatable with the driving member.

20. An engine starter drive including a driving member adapted to engage a member of the engine to be started, means for enforcing engagement of said members, and a coiled drive spring cooperating with the driving member and having its coils continually in contact in order to provide frictional resistance between them which delays the unwinding of the spring after being Wound in the application of power in the operation of starting.

21. An engine starter drive including a driving member adapted to move longitudinally to engage a member of the engine to be started, means mounted for longitudinal movement and, in its longitudinal movement continued after any improper arresting of the longitudinal movement of the driving member, cooperating with such driving member to enforce proper engagement thereof with the engine member, and means cooperating with the driving member for storing up energy in the operation of starting and for gradually delivering its energy thereafter.

22. An engine starter drive including a driving member adapted to move longitudinally to engage a member of the engine to be started, 'means mounted for longitudinal movement and, in its longitudinal movement continued after any improper arresting of the longitudinal movement of the driving member, cooperating with such driving member to enforce proper engagement thereof with the engine member, and a coiled drive spring cooperating with the driving member and having its coils constructed andarranged to provide frictional resistance between them against unwinding after being wound in the, application of power in the operation of starting.

23. An engine starter drive including a rotatable member, a driving member mounted thereon and actuated thereby and formed in two parts, the second part being adapted to be moved by the first part into engagement with a member of the engine to be started and to be drivingly rotated by such first part to crank the engine, and means cooperating with said two parts for causing a slight rotary movement of said second part when the latter is arrested in its longitudinal movement.

24. An engine starter drive including a rotatable member, a driving member mounted thereon andactuated thereby and formed in two parts, the second part being adapted to be moved by the first part into engagement with a member of the engine to be started and to be rotated by such first part, said two parts having' on'their adjacent faces cooperating cam means for causing a slight rotary movement of said second part when the latter is arrested in its longitudinal movement.

25. An engine starter drive including a driving member mounted for longitudinal movement and for rotary movement and adapted to engage and crank a member of the engine to be started, and means including a single structural element for shifting the driving member longitudinally, said structural element and driving member having cooperating means for causing slight rotary movement of'said driving member in the event of and during the abutting of the driving member and the engine member.

ing abutting of the driving member and the engine member.

27. An engine starter .drive including a driving member longitudinally movable to engage and rotatable to crank a member of the engine to be started, a structural element for coaction with said driving member and having provisions cooperative wiht provisions of the driving member to longitudinally advance the latter, drivingly rotate it, and cause slight rotary displacement thereof relative to such element in the event of and during the abutting of the driving member and the engine member, and means for actuating said element.

28. An engine starter drive including a driving member longitudinally shiftable to engage and rotatable to crank a member of the engine to be started,'means to shift said driving member longitudinally, said means includin a member coaxial with said driving mem er and having provisions cooperative with provisions of the driving member to shift the latter, rotate with it, and rotatively displace it slightly relatively to said coaxial member in the event of and during the abutting of the driving member and the en.

gine member and means for actuating said shifting means.

- 29. An engine starter drive including a; driving member longitudinally movable to engage and rotatable to crank a member of v the engine to be started, a control member operatively associated with said driving memher and having provisions-cooperating with provisions-of said driving member to advance the latter longitudinally and cause slight rotary movement thereof relative to said control member in the event of and during the abutting of the driving member and the engine member, said control member being 00- axial with and in tandem relation to said driving member and arranged fornormal rotation therewith and means for actuating said control member.

WILLIAM L. MoGRAT-H. 

